Storage devices based on NAND flash have good average latency; however, the worst-case latency, referred to as “tail latency” can be much longer. Providing more predictable latency in a NAND flash storage device may be beneficial in some applications of NAND flash technology; for example, in NAND flash-based storage devices and swap devices. A swap device can serve as extended memory space, sometimes referred to as swap space, in a computing system. The swap device can represent a tradeoff between the faster speed of RAM and the lower cost of alternative memory/storage mediums such as a hard disk drive (HDD) or a solid state drive (SSD). An SSD based on NAND flash, while faster than an HDD, may suffer from unpredictable tail latency due to the way NAND flash chips operate.